Lifting jack



March 1 1927.

1,619,304 L. D. NILSON LIFTING JACK Filed July 215, 1926 v 4 Sheets-Sheet l M gyW/W/zmM/df//mg 1,619,304 March l 1927 l.. D. NILSON LIFTING JACK 192 March l 7 15D. NlLsoN gLIFTING JACK4 Filed July 2e, 192e 4 sheets-sheet 4 Patented Mar. 1, 1927..

unire stares inlener? e lTenir FFicE.

LEONARD D. NILSON, 0F VArYZA'IA, MINNESOT, AS.SlGllllB.-iiiY MARQUE'TTE MANU- FACTURING COMPANY, OF ST. PAUL, MNNESOTA. v

LIFTING Jaen.

Application filed July 26, 1926. Serial N0. 125,011.

tomobile service work wherein an automobile may be lifted quickly and easily for supporting one end thereof in position where the tire may be removed from the wheel of the automobile.

More particularly it is my object Vto provide a lifting jack adapted to engage ay poi-,

tion of an automobile spaced only a few inches above the ground and capable ofraising the same to a substantial distance above the ground, the parts being very simple, durable, and efficient.

Still a` further object is to lprovidey aframe having a curved notched member fiXedA thereon and a load lifting arm having mechanism thereon and carried thereby for engaging the fixed curved member, the load lifting arm being raised through the en- O'avement of the mechanism carried thereby :n e with the curved member. Y

Still a f urtherfobject is to provide a fixed notched sector and .a movable lifting arm and mechanismv carried by the loady lifting arm for engagement with the notched sector, and means for operating` the mechanism carried by the load lifting arm for imparting movement to the load lift-ing arm.

Still a further object is to provide a notched sector and a swinging load lifting arm having a lifting pawl and a locking pawl movable relative to thelifting'arm and mounted thereon`r the pawls being adapted to engage the notches in the sector in a step by step relation, and an operating handle connected to the lifting pawl whereby operation of the handlev will cause the lifting arm to swing relative to the lifting pawl, carrying with it the locking pawl, and after the lockingv pawl has been moved from one.

notch to the next notch, then the lifting pa-wl its-elf becomes free andis permitted to be moved while the liftingarm remains fixed and permitting the lifting vpawl to assume a position in the' next notch where movement of the swinging arm may again be repeatec Still a further object is'to provide a lifting jack wherein movement of the lifting arm vis imparted thereto through a connection between the lifting pawl and the` swinging arm-itself.

. Still another object is toprovide a control device for reversing the action of the liftingi and locking pawls for ,permitting the load lifting arm to be lowered in a step by step movement so long as the load isupon the lifting arm and thereafter said control mechanism functioning for rendering both ofthe pawls inoperative (and permitting the load lifting arm to assume its normal starting Y position.

- St'll ka further object is to provide a lifting pawl carrying` framepivotally mounted upon the load lifting arm and capable of pivotal movement relative to the liftin pa-wl mounted Vthereon andrelative tothe lifting arm. Y f

lVith these and 'other objects in View7 my invention consists in the construction, ar-A rangement and combination ofthe vvarious parts of my device, whereby the objectscontemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in

which: y Y

Figure 1 is atop plan view of my improved lifting jack with parts shown in sectionl to' illustrate theconstruction.

Figure 2 is a. sectional view taken on line Q-2 ofFigure 1, parts being broken away.

Figure 3 is a detail view of 'aportion of the operating handle and the control member mounted thereon.

Figure 4 is a side kview ofmy lifting jackV illustrating the load lifting arm in itsdown position in solid lines and in its raisedV postion in dotted lines.

Figure 5 is a sectional view taken onv line n 5-5 of Figure le, illustrating the lifting arm and mechanism carried thereon in its raised Figure 9 is another view illustrating theV locking and lifting pawls in another of their 6 is a detail sectional view' taken l Figure 5, illustrating the loadl 26 thereon.

positions with the load liftingr arm traveling downward.

Figure l() is a sectional view taken on line 1.610 of Figure 2; and

Figure Il is a detail sectional view taken on line 11u11 of Figure 2.

In the accompanying drawings` I have used the reference numerals 1.6 and i9 to indicate a pair of axles upon which mv lifting jack is assembled- The axle 16 has a sleeve 14 thereon whit-h has its ends rest-ing against a pair ot triangular shaped plates iGwhieh torm a portion of the supporting frame ot the lifting jack as will hereinafter be more tnllv deseribed.

The `plates 16 are eaeh formed with openings through which the axles 16 and i9 extend. On the `end of the axle i6 l'iemvond the plates 16 I mount short spacing sleeve i8 upon which are lionrnaled wheels Q6. rlhe ends of the axle 16 are threaded and nutsv Q2 are placed thereon for holding the wheels E26 in position and at the same time holding the sleeves 18 and the sleeve i4 1n engagement 'with the frame plates I6, Similar sleeves i6 are mounted upon the ends of the axle l2 and the ends of the axle l are also formed with screw threads and reeeive nuts The upper corner of the plates i6 are connected together b v a holt 24 which has one of its ends screw threaded and receives a nut tween the frame plates i6 eaeh have a pair of spacing sleeves 28. i

`Received upon the axle 1Q and between the spacing sleeves 2S. is a curved notched member or seetor 536. The notched sector may be formed with ribs for reinforcing purposes and the ends there of are formed with openingstor receiving the bolt 24 and the axle i2. "Upon the sleeves `18, rmounted upon the axle 12 are iournaled wheels 26 similar to the wheels 26 upon the axle 16.

`From the construction of the parts just described, it will be seen that the :trame plates I6 are held in spaeed apart position and that the notched seetor` 36 is held therebetween upon the axle ,l2 andybolt Q4. The parts just described may properlyr he called the supporting frame of invlifting jack.

Iivoted to each trame plaie i6 upon a pivot holt or the like 34 a lifting arm 36; It will he noted that I have provided a pair of lifting arms 36 although a. single arm mav be used. I have illustrated in the drawings snob. construction and materials as will enable the lifting jack to be made ofvsheet iron by stampings although the parts inav be Iliade of castings. The lifting arms 36 are spaced apart. The outer or 'tree ends ot the lifting arms 36 are connected together b v a spindle 0r the like 36. A loadlit'ting `head or member 4 6 is earried b v the spindle 38 and received between the two spaced lit"- The axle 12 and the bolt Q4 be-` and the holt teurere@` ing; arms 36 as elearly illustrated in Figure 6 oit' the drawings. The load liiting head is substantially yoke shaped and has a lrnnrled or roughened head 42 and serves 'tor engaging a portion of an automobile or other vehicle.

Spacing sleeves or washers Ai--t are interposed between the sides of the member 46 and the arms 36. A sleeve 46 is also provided upon the spindle 36 and is received between the two arms oit the member 46 as clearly illustrated in Figure 6 of t-he drawings. p

A` pair `oi stabilizingr arms 48 are connected to a spindle 66 which is jourualed in the member 46 above the spindle 38. Iashers or the like are interposed between the stabilizing arms 48 and the member 46. The free ends of the stabilizing arms 48 are pivotall3T connected to the Asleeves 28 upon the bolt: 24;

`From the construction ot the parts 'just described it will be seen that the lit-ting arms roughened portion 42 ofthe member 46. i

The position just described is elearl \v illustrated in Figure 2 of the drawings.

The extension head 54 is pivotallv supported by the pivot member 56, journaled in tbe ears 5S formed on the niember 46 it-sel't. rlbe extension bead .64 maw,7 be moved through fifnlrstantiallv ninetyT `degrees and when iu this position will not interfere with the tre use of the member 46 itselt and partienlarlv the rouSrhened surtaee 42 thereof.

The extension head 54 may have a stop 66 thereon tor engagement with a portion ot the member 46 Jfor holding the extension head 54 in its substantiallv horizontal position or inoperative position.` The extension head is onlyY necessary when it is desired to engage a member that the original starting` position thereof is suhstantiall;v high above the ground and where the lift7 is comparativetv high.

The two spared members 36 which coustitute the littingarms are eonnccted together intermediate ot their ends bv a trans verse holt or pivot memberftil. Pivotallv mounted upon the bolt 62 and between the two arms 36 are a pair ot triangular shaped eariving frame plates 64. The plates 64 are in turn connected together liv a separate pivot member or bolt 66. Mounted upon the bolt or pivot 62 is a locking pawl 68. The looking pawl 68 .is received between the two carrying fame plates 64 and is adapted to lil() Cil therewith. i

`engage the notched sector 30 clearly il- `cam surface extension 70 theV purpose kof which will be hereinafter.

forth. p

T he locking p'awl (58 is mounted upon the pivot bolt 62 and is capable of movement in dependent of the mov-ement of the pawl carrying frame plates 64.- Be'tween the two carrying frame plates (il and piv-otaliy more `fully l set- Vlnot'tnted upon the pivot bolt (S6 is a lifting Jawl 72 adaoted to enOaO'eV the notches 7% of l l C b Y the notched sector 30.

From the construction of the parts just described, itl will be seen that pivotal movement of the two carrying plates'tll upon the bolt rwill cause the lifting pawl to be carried The lifting pawl 7 2 is formed with a cam extension 76, the lpurpose of which will hereinafter be more `fully set forth.

The locking' paw'l 68 and the lifting pawl 72 are connected together by a. spring 7S. rThe spring 78 has one of its ends anchored to an extension 8O upon the liftingV pawl 2 and has its other end extended through an opening 82 formed in the locking pawl itself Y as clearly illustrated in Figure 2 of the drawings. rlli-e spring 78 tends to hold the locking and lifting pawlsv always in 'engage ment with the notched sector 30.

An operating handle 8e is pivotally mountd upon the sleeves 28 which are mounted upon the axle 12'. The operating handle Si is formed of strap material connected together at one `end by a' handfengaging: piece 86. The side members of the hand-le 84 eacn have short plates 858 connected thereto in any suitable manner, preferably by rivets 90. The plates S8 have a pivot bolt 92 journ'aied therein to which are fixed a pair of spa-'ced pull bars 94. The pull bars in tu-rn are piv- Pract/ical operate-0n. for raising the Z'z/ftvifnlf/ arms.

y l will now describe the operation of my lifting` jack for havingit move from the position shownl in solid lines in Figure ft to 'the position shown in dotted lines. p In Figure 2 I have shown Vthe locking pawl 68 in engagement with the bottom notch 74 and the lifting pawl in engagement with another of the notches Tel. above the notch that the locking` pawi is in. In this position the operating handle 8l is moved in a downward direction as indicated by the arrow 98 which causes the pull bars 94 to movein the direction indicated by the arrow 100. This movement in notched sector f and as soon Vas the locking pawl 68 is yout of the notch it is in 1n Figure turn pulls the carrying frame forwardly and causes it to pivot around the pivot point or bolt 66 of the lifting pawl 72. yThe carrying frame' (ifi pivots in the direction indicated by the arrow 102. The result of this movement is to carry with it the lifting arms The lifting arms 36 being fix-ed so far as the locking pawl is concerned causes the locking pawl 68 to be withdrawn from the 2 then the springCS immediately causes it to be pulled towards the lifting pawl 7 2 and this pulls the locking pawl into the notch just below the notch that the lifting pawl 1s in.

The locking pawlthen holds the load lifting arm 36 in its stepped up position. The operating handle is then move-d upwardly `a short distance. This movement" imparts a. rearward movement to the pull bars 94 in a direction indicated by the arrows lOLl. This in turn swings the carrying plates 6i upon the pivotbolt- 62 and at the same time carries the lifting pawl and' pulls it out of engagement with one of the notches 74 of the sector 30. The spring 78 tends to hold the lifting pawl always inf'ene gagement with the sec-tor itself and as soon as the carrying frame plates tia have beenV swung upon their pivot 62 a suthcie'nt distance for the lifting pawl to clear the one notch that the lifting pawl was originally in then the spring functions and returns the lifting pawl into engagement 'with the next:l 00

Eao

to assume' the next above notch, the loc-king pawl 68 holds the lifting arms 35 in a tiXed position relative to the sectorBG. After the lifting pawl has assumed the next above y notch then the handle 84' is `again moved downward in the direction indicated by the arrow 98. The carrying frame plates 64e are then moved again upon the pivot bolt 66 as an axis for imparting a lifting swinging movement to the lifting arms 36 and movement of the locking pawl from one notch to the n :it above notch. The action is repeated and the lifting armsare moved upwardly in a step by `step movement. It will be noted that the lifting arms carry practically all the ,-iechanism used for liftingA them and lfor holding-them in their lifted position.r The carrying frame plates 64e serve as the connectionv by which the operating handle transmits. upward movement to 'the lifting arms. The carrying frame at the saine time serves as the means for permittingthe lifting pawl to adi fulerumor Operario/i for Maiori-alf; Uffing orma.

l will now deseribe in detail the meehamsm tor `(rontrollinar the `locking.r and lifting' pawls l'or permitting' them to operate in sut-h manner as to permit the load to be lowered 1n a step by step downward movement through the operation ot the operatingT handle. i

lllouuled upon the sleeve Llo is a cam engaging lever ltlt which has cables `10h tened tota vole nieniberi l1() which in turn is fixed to the tree fad ot the lever 10G. The level' 10t designed to engage the cam extension TO upon the lochine' pawl (38 and the cam extension 'To upon the liltine pawl T2. The cables 10S extend around pulley wheels 112 which are mounted upon the two lifting arms ."t. The cailles' then `extend around palle)Y wheels 114 mounted upon the pivot bolts 34: of the lifting' arms 236. The cables then extend around pulle \y wheels mounted upon the sleeves on the axle l2 whereby the cables extend around the pulleys at the pivot point or connectionubetween the operating handle and the supporting traine. The purpose oi providing the arrangement ot pulleys as here illustrated is to permit free use of the operating handle without in any wa)Y affecting the lever ltltl or applying' undue tension upon the lever 10G. The cables 108 have coil springs llt eonneeted thereto whieh in turn are ronneeted to wires 118. The wires 118 project along; the sides ot the operating;r handle Si and `are connected to a pivot ed hand piero 120. The hand piece 120 is pivotalli`- mounted upon the operating?y handle S4 as at 122.

The lever 106 does not atleet the hitting' and looking pawls duringr upward movement of the lifting' jack and onli,Y :functions when the lifting: jack is beingf moved downwardly and in order to cause it to function, it is necessary to swing the hand piece 120 l'rom its solid line position in Figure il to its dotted line position at which time the springs 116 will be placed under tension causing a downward pushingr movement of the lever 106 against ther-ain extensions TO and TG during opfn'ation of the litlinpg and loelting i pawls.

The hand piene 1Q() and the ronneetion ol the wire 11S` therewith ol such nature. as to cause the hand piene to assume a passed over center position when thehand piece is in the position shown in dotted lines in Fie'- ure During the down movement ot the lifting jack and while a load is resting upon theload inemher 'el-t), the lever proving the load downward `is 1.06 operates as I will now describe.

Assuming that the starting` position for the position shown in Figure 5 ol' the` drawings, the lifting: pawl 7:2 is then in engagement with one of the notches in the sector 30. The lever 120 is moved to dotted line position as shown in Figure 3 o the drawings. The lever 106 then engages the eam extension 7G as wellas the earn extension on the loeking pawl G8. Upward movement of the operatin1 handle Set will impart movement to the pull bars in the direction indio-ated h v the arrow 121 in Figure 5 ol the drawings. o

rl`his `upward n'ioveinent will cause the 'verifying plates (i4: to swine' about the pivot` titl and the engagement of the lever 10G with the `rain extension T0 will render the coil spring` T8 inoperative and the locking' pawl GS will be held out olf engagementwith the notched sector ltl. Further n'iovelnent oit the carrying trame (il will eaue-e the cam exten- .sion 70 torlree iitsel'l .troni the lever 10G as elearlv shown in Figure ot the drawings, the lever 10G being held in its raised position bv the cani extension 7G on the lifting pawl 79.

As soon as the extension T0 is released l'rom Contact `with the lever 10h` then the coil spring; 78 immediately 'functions tor pullingr the looking' pawl `into engagement witlrthe notched seetor lll and the parts then assume the position shown :in Figure 7 ol the drawings.

After the loelrinp; pawl (3S has assun'ied the position shown in Figure 7 of the drawn innsi then a slight amount ot upward movement of the o] )eratin;r handle pulls the litt ingr pawl a trom the noti-hed sector 30 and then the engagementojl the lever 106 with the ealn extension TG pushes the liftingr pawl out` of ennagenient with the notched sector and holds it out ot engagement. Alfter the lifting pawl T2 has been moved 'trom theposition shown in Figure 7. of the drawings to tho position shown in Figure 8 ol'V the drawingsq then downward movement o't the operating` handle imparts movement to the pull hars 9st in the direetion indicated bv the arrows 126. This` movement causes the Carrying; -trame (il to pivot .upon the pivot bolt ($2 throwingr the li'ttlngr pawl downwardly. As the lifting` pawl and carrying frame (Si are moved relative to the pivot bolt (i2` the einrzurenient ot the lever' 10G with the extension T0 is discontinued and then the eoil sprirnef TS functions 'for iinnnidiateliv forcing the littinnl pawl into the notrh just lielor.' the noteh that it previousl'v ocrupied. ',lhe engagement ot the lever 10G with the cam extension 7G remains until after the downward movement of the lifting pawl is ojl sullieient distance so as to pass over the upper edge oftnis notch and this, of course, insures the liiting provi to oef sume the notch next below Vthe notch that it was originally l Continued movement ot the operating handle 8st and the movement ot' the pull hors in the direction in` looted hy the arrows l2@ releases the looking peni 35 com extension 7,0 thereof to. engage with `the lever 106, thus throwingtlie looking pawl outwardly and away from the notehee sector 30, the lifting 'pn-Wl lthen being yin engagement with the notched sector 30.

As soon as the lookingv pawl 68 has been disengaged from the notched ,seotor 30 and as soon as the cam eXtensionTO disengeges the lever 106, then the springZS fonctions foriaganpulling the looking pewl into the engegement with the next below notch. The

lever 106 functions for holding the ooil spring Y Instant releasev operation. The loed itself upon thelond lifting .erin

' prevents the lever 106 from .throwinghotli the locking and lifting psvvls out of ongege-- ment with the notched sector, .The load, of

course., is snieient to overcome the tension of the soil springs 1 16. i

As soon es the load is released from the lood lift-ing then the oo-il springs ',116 are of suflioient strength to conse the lever lO to engage yboth of the psivls and throw them eiviay from the notched seotor to the position shown in dotted lines in `Figure 5, et which time, the entire lifting erin and mechanism carried thereby will drop to its, originel starting position, f

It will be noted that one of the advantages of my lifting jock resides in the mounting of the entire lifting mechanism itself npon the lood lifting erm ond carrying it with the loud lifting girm during either the upward orv downward movement of the lood lifting erm.

Another `advantage resides in the arrangement whereby the load itself insures engagement of the looking` and lifting parvis With the notched sector during downward movement and as soon ns the load is no longer supported upon the-lifting; firm, then the control mechanism7 particularly ther `Coil springs 116, are of sniiic-ient strength to push the lover i106 ngziinstthe looking' and lift-ing piuvls for causing them to free themselves ind onuses the from. the notched seetor 30l end permitting the lifting arms and mechanism carried thereon to drop to its starting position. The lifting armsswng :upon .their pivots. and always retein the lifting and looking pewls,

position ivliere they will engage the seo-vtor, evenif though the lifting and loolng pfuvls themselves are oepelole of movement relative to the lifting arms.l

Some v@hongos may he made in the oonstruetion end' arrangement of the various ports. oi my invention, without deperting from `the reel spirit-fold purpose of; my venton', and it is my intention to oever by niy claims any n'iodiiied forms of structure or use of ineehenieel equivalents, Whioh may be reasonably'inoliided Within their soope.

l claim es my invention; t

l, A lifting joelr comprising e supporting ironie,e1iotel1ed sector lined relotiveto seid frame., pivotedloed lifting erin, e porvi Carrying freine pivotedto seid erm and earried therewith, o lifting p21-Wl pvoted to seid carrying freine et e point spooed from theV pivot point of said carrying frame and engegesble with sold seetor end moons oon-V neeted to said carrying freine for importing movementto seid lifting erm.

2. A lifting joel; comprising e supporting Y freine, .e no tohd seetor fired relative-to seid freine, e pivoted lood lifting erm, e pewl Carrying mounted on and movable,

relative to sold erm and earned therewith., e

lifting powl vpivoted to seid Corr-ying frame et e point speoed from the -eonneetion loetween seid lifting erin and. seid Carrying freine sind engageable with said sector, and

ineens connected to seid Carrying fra-me forv `imparting movementto seid. lifting erm. i

8. Alifting 'jock comprising e supporting frame, e notehed seotorlred reletive to seidv freine, o e pivoted' lood lifting erm, ey powl. carrying frame pivoted to seid erm pond eer-y ried therewith, o lifting povvl pivoted to seid carrying froment o point spaced from the pivot point of seid Carrying frame end engagenhle with said sector, ineens connected to seid carrying frame for imparting movement to seid lifting erin, and looking poWl pivoted to seid erm and eerried thereon for. engaging the no tehed sector end looking the srrn against movement in one direction.`

4l. A lifting nook comprising e supporting fra-mma noto-hed seotoriiiged relative to said i frame, :t pivoted load lifting arm, t powl carrying freine pivoted to seid arm find can ried theretvitlngtlifting pewl pivoted to said' i carrying frame at a point spaced from the pivotpojint offsaid carrying frame and ene gngeahle with said sector, means Connected to said -Carrying freine'for imparting movement to said lifting arm, and a looking pawl pivoted to seid arm and oarried'thereon for'A engaging the notchedsector and looking the arm against movement 1n one direction, and

iso

with said notched sector and means for imparting movement to said pawl carrying frame relative to said lifting arm.'y y

13. A lifting jack comprising a wheel mounted frame, a curved member having a series of knotches therein, a swinging load lifting arm pivoted on said frame, a lifting pawl and a locking pawl operatively connected to said'arm and carried thereby, said pawls adapted to engage said notches in step by step relation for upward movement, an' operating handle operatively connected to said lifting pawl whereby operation 'of the handle will causethe arm to swing relative to said liftingV pawl carrying with it the locking pawland pulling it from one notch to the nextnotch for locking the arm in itsV moved position, said lifting pawl, after the locking pawl has moved, being free to move while the lifting arm remains fixed for assuming apposition in the next notch where the action of swinging the arminay be repeated.

14. lifting jack comprising a wheel mounted'frame, a curved member having a series Aof notchestherein, a swinging load lifting arm pivoted on said frame, a lifting pawl and a locking pawl operatively connected to said arm and carried thereby, said awls'adapted to engage said notches in step Ey step relation for upward movement, an operating handle operatively connectedl to saidlifting pawl whereby operation of the handle will'cause the arm to swing` relative to said lifting pawlV carrying with it the locking pawl Vand pulling it from one notch to the next .notch for locking the arm in .its moved position, said lifting pawl, after the locking pawlhas moved, being free to move while vthe lifting arm remains xed for assuming a position in the next notch where the action of swinging the'arm may be repeated and control means for reversing the action of said pawls and permitting` the lift- 'ing arm to be lowered in a step by step movement.

15. A lifting jaclrcomprising a wheely mounted frame, a curved member having a series of notches therein, a `swinging' load lifting yarm pivoted on said frame, a lifting pawl and a locking pawl operatively connected to said arm and carried thereby, said pawls adapted to engage said notches in step by step relation for upward movement, an operating handle operatively connected to said lifting pawl whereby operation of the .handlewill cause the arm to swing vrelative to said lifting pawl carrying with it the locking pawl yand pulling it from one notch tothe next notch for locking the arm in its moved position, said lifting pawl, after the locking pawl hasmoved, being free to move while the lifting arm remains fixed for assuming a position in the next notch-where the action kof swinging the'arm may be rep'eatedvand control means for reversing the action of 'said pawls and permitting the lifting arm to be lowered in a step by step move ment, so long as the load is upon the'load lifting arm. y 16. A lifting jack comprising a wheel mounted'frame, a curved member having a series Vof notches therein, a swinging load lifting arm pivoted on said frame, a lifting pawl and a locking pawl operatively conf nected to said arm and carried thereby, said pawls adapted to engage said notches in step by step relation for upward movement, an operating handle operatively connected t-oV saidlifting pawl whereby operation of the handle will cause the arm to swing relative to said lifting pawl carrying with it .the locking pawl and pulling it'from one notch to the next notch for locking the arm in its moved position, said lifting pawl, after the. locking-pawl has moved, being free tomove while the lifting arm remains fixed for assuming a position in the next notclrwhere the action of swinging the arm .may be repeated and control meansfor reversingthe action of said pawls and permitting the lifting arm to be lowered in a step by step movement, said control means including spring means for holding both of said pawls out of engagement with the' notched .f member when the load upon the load lifting arm is released. f

17. A lifting jack comprising a wheel Y mounted frame, a curved member havinga series of notches therein, a swinging load lifting arm pivoted on said frame, a lifting pawl and a locking pawl operatively conf nectcd to said arm and carried thereby,said pawls adapted to engage saidnotclies in ste) by step relation for upward movement, anv

operating handle operatively vconnected to Y said lifting pawl whereby operation of the handle will cause the arm to swing relative to said lifting pawl carrying with it the locking pawl and pulling it from one notch to the next. notch for locking the arm in its moved position, said lifting pawl, afterthe locking pawl has moved, being free to move while the lifting arm remains fixed for assuming a position in the next notch where the action Vof swinging the arm may be repeated and control means for reversing the n action of said pawls and permitting the liftingarm to be lowered in a step by step movement, so long as the load is upon the loadl lifting arm, said control means after the load upon the load lifting arm is released, functioning for holding both of said pawls ont of engagement with said notchedmember and permitting the lifting arm to drop.

18. A lifting jack comprising a wheel. mounted frame, a curved .member having a series of notches therein, aswinging load lifting arm pivoted on; said frame, `a pawl,y

carrying frame pivotally Vsupported upon V30;

*said arm, a lifting pawl on said carrying frame at a point spaced from `the pivotal connection between said carrying frame and said arm, a. locking pawl on said arm, said arm, said locking pawl holding the arm in its moved position and permitting the paivl carrying frame and lifting pawl thereon .to pivot relative to said arm'and allow the lift-l lng pawl to assume a position in another ot the notches.

19. A lifting jack comprising a frame, a curved member having a series of notches therein, a pivoted load lifting arm, a pawl carrying frame and a holding paw] pivoted i on said load lifting arm,a lifting pawl pivoted to said pawl carrying frame, an operan ing handle operatively connected to said pawl c: rrying frame for causing pivotal movement of the pawl carrying frame relative to the load lifting arm whereby the lifting paw] is moved to engage one of the not-ches in said curved member when the handle is moved in one direction and for causing pivotal movement of the pawl car-` rying frame about the lifting pawl as a pivot when the handle is moved in the other direction for raising the load lifting arm.

20. A lifting jack comprising a `frame, a curved member having a series of notches therein, a pivoted load lifting arm, a pawl carrying frame and a holdingr pawl pivoted on said load lifting arm, a lifting pawl pivoted to Said pawl carrying frame, an operating handle operatively7 connected to said pawl carrying frame for cansing pivotal movement of the pawl carrying frame rela tive to the load lifting arm whereby the lift ing pawl is moved to engage one of the notches in said curved member when the handle is moved in one direction and for causing pivotal. movement of the pawl carrying frame abont the lifting paiwl as a pivot when the handle is moved in the other direction for raising the load liftingr arin and moving the holding pawl to position for en gaging the next above notch, spring means for holding said pawls in engagement with the curved member and control means for reversing tl i action ol' said pawls and pei mitting the liftingarm to be lowered in a step by step niovement.

21. A lifting jack comprising a wheel i'nounted frame` a` curved member having a series of notches therein, a swinging load lifting arm pivoted on said frame, a lifting pawl and a locking pawl operatively connected to said arm and carried thereby, said iawls adapted to engage said notches in step y step relation, an operating handle opera# tively connected to said lifting pawl whereby operation of the handle will canse the arm to swing relative to saidlifting pawl carrying with it` the locking pawl andpnlling it from one notch to the next notch for locking the arm in its moved position, and a eonnnon spring for holding said pawls in engagement with the curved member, said lifting pawl, after the locking pawl has moved, heilig free to move while the lifting arm rei'nains fixed for` assuming a Josition in the next notch where the action o swing ing the arm may be repeated.

22. A lifting jack 'comprising a frame, a curved member having a series of notches therein, a pivoted load lifting arm, a` paavl carrying 'trame and a holding pawl pvoted on said load lifting arm,a lifting pawl pivoted to said pawl carrying frame, an operating handle operatively connected to said pawl carrying frame for causing pivotal movement ot' the pawl arrying frame relative to the load lifting arm whereby the lifting pawl is moved toengage one of the notches` in said curved menibcr when the handle is moved in one direction and for causing pivotal n'iovement of the pawl carrying frame about the lifting pawl as a. pivot when the handle is moved in the other direcs tion for raising the load lifting arm and moving the holding pawl toposition for engaging the next above notch, means for reversing the action of said pawls for lowering the load lifting arm, said means comprising a. lever pivoted to the load lifting arm, and 1n'ojections on said pawls designed to be engaged by said leverl for maintaining the pawls disengaged from the notches in said curved member.

23. A lifting jack comprising a frame, a curved member having a series of notches therein, a pivoted load lifting arm, a pawl carrying frame and a liolding pawl pivoted on said load lifting arm, a lifting pawl pivoted to said pawl carrying f lame, an operating handle operatively connected to said pawl carrying frame for causing pivotal movement of the pawl carryingframe relativo to the load lifting arm whereby the lifting pawl is moved to engage one of the notches in said curved member when the handle moved in one direction and for causing pivotal movement of the pawl carrying frame about the lifting pawl as a pivot when the handle is moved in the other direction for raising` the load lifting arm and moving the holding pawl to position for engaging the next above notch, spring means for holdingsaid pawls in engagement with the curved member and means for rendering said spring means inoperative for lmvering `the load liftingl arm, said means comlirising a lever pivoted to the load lifting arm. and projections on. said pawls designed to be engaged by said lever for maintaining the pawls disengaged from the notches in said curved member.

ing arm is raised, a reversing control device for engaging said pawls for reversing the direction of movement of the load lifting arm.

25. A, lifting jack comprising a frame, a curved member having a series of notches therein, a pivoted load lifting arm, a pawl carrying frame and a holding pawl pivoted on said load lifting arm, a lifting pawl pivoted to said pawl carrying frame, means for actuating said pawl carrying frame whereby said pawls are caused to successively engage the .notches in said curved member with a step by step movement and said load lifting arm is raised, resilient means for causing said pawls to engage said notches, a reversing control lever pivoted on said load lifting arm, cams on said pawls, means for causing said lever to resiliently engage said cams for moving said pawls for disengaging them from said notches.

26. Aliftingjack comprising a frame, a curved member having a series of notches therein, a pivoted load lifting arm, a pawl carrying frame and a holding pawl pivoted on said load lifting arm, a lifting pawl pivotedto said pawl carrying frame, means for v actuating said pawl carrying frame whereby said pawls are caused to successively engage the notches in said curved member with a step by step movement and said load lifting arm is raised, resilient means for causing said pawls to engage said notches, a reversing control lever pivoted on said load lifting arm, cams on saidpawls, means for causing said lever to resiliently engage said cams for moving said pawls for disengaging them from said notches, the cam on either of said pawls serving to disengage said lever from the cam on the other pawl thereby allowing said other. pawl to engage a notch in the curved member.

. 27. A jack comprising a notched member. a load lifting arm provided with a pawl carrying frame, said load lifting arm and said pawl carrying frame being provided with pawls, means for causing said pawls to 'engage the notched member, cams on said pawls, a lever for engaging said cams for rendering said means inoperative, movement of said pawl carrying frame in one direction causing the cam on one of said pawls to disengage said lever from the cam on the other pawl whereby said other pawl is free to engage said notched member and vice versa.

28. A jack comprising a notched member, a pawl frame having a pair of pawls pivoted thereto for coacting with said notched member, spring means for causing such coaction, a load lifting arm carriedby said pawl frame, means for rocking said pawl frame whereby said pawls will engage said notched member in a step by step movement, a reversing means for said pawls comprising a lever, for rendering said spring means inoperative, cams on said` pawls the rocking movement of said pawl frame causing the cam Ion one of said pawls to engage the lever and cause its disengagement from the cam on the other pawl for allowing said other pawl to engage said notched member and vice versa.

Des Moines, Iowa, J une 30, 1926.

- LEONARD D. NILSON. 

